A requirement has long existed for markers which can be installed in such a way as to delineate visually the path to be travelled by vehicles. In some cases, as when a roadway is being repaired, the markers are portable, reusable and employed only for short periods of time. In those cases, the requirements have been met by conventional barricades equipped with flashing lights, by the well known "marker cones" fabricated from polymeric material, and by other devices. A more difficult problem arises when it is necessary to provide relatively permanent delineation of highways, airport taxi strips, vehicle parking lots, and the like. For such purposes, it has long been common practice to employ wood posts, suitably treated, painted and installed in the manner of fence posts. Though wood posts have the obvious disadvantage of breaking when struck by a vehicle, they were accepted for many years, but changing circumstances have made wood posts undesirable for a number of reasons. One reason is that the cost of using wood posts has become excessive, due to the increased cost of the post itself, the markedly increasing cost of replacing broken posts, and the cost of maintenance. A perhaps more important reason in the case of highway marker posts results from increased vehicle speeds and traffic densities. When a wooden marker post is struck by a vehicle travelling at a relatively high speed, the post is sheared off and the main body of the post, being freed by the impact, becomes an airborne hazard. On occasion, the body of the post strikes the windshield of a moving vehicle, injuring or killing the occupant.
Seeking to solve such problems, prior-art workers have sought to provide, as replacements for the wooden marker posts, markers made from polymeric materials. U.S. Pat. Nos. 1,668,288, 3,502,007 and 3,709,112 disclose examples of such prior-art efforts. For many applications, particularly those in which the marker is likely to be struck by a vehicle travelling at a substantial speed, or run over by a vehicle at any speed, prior-art proposals have not completely solved the problems, principally because the markers have not been able to satisfy the requirements of long term use and use under winter conditions.